This application claims the priority of German patent document 100 09 157.1, filed Feb. 26, 2000, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a fluid actuating drive which is operated with a hydraulic or pneumatic supply, for mutual displacement of two structural parts.
German patent document DE 4312503 A1 illustrates a folding bellows, with two mounting parts that move relative to one another. When activated, the bellows moves outwards or inwards across its folds. The direction of the forces thus applied on the mounting parts depends upon the operation of the mounting parts or of the components arranged accordingly on them. Hence, a high mechanical guiding force is required for components that extend over a relatively large area transverse to the direction of movement. A hydraulically operated spring bellows is described in German patent document DE 3420557, which is coupled with a pneumatically pressurized cylindrical chamber. The spring bellows is bent in a circular arc, in order to act in conjunction with a swivel bracket with the cylindrical chamber acting as a shock-absorbing element. The spring bellows is introduced into a housing with a circular cross-section. A suitable converter is required for converting the swivelling movement into a translational movement. Apart from this, appropriate mechanical guidance of the components moving against each other is also necessary.
A disadvantage of state of the art actuating drives is that the forces that act upon the structural components as a result of the actuating forces, can be conducted into these components only locally. As a result, comparatively greater forces are generated locally on the connecting points between the actuating drive and the structure, thus making it necessary to install expensive force transmission devices on the structure components concerned.
One object of the invention therefore is to provide a fluid actuating drive for effecting smooth adjusting movements that transmits the forces the concerned components as uniformly as possible.
Another object of the invention is to provide such a fluid actuating drive that is simple, space-saving and light-weight.
These and other objects and advantages are achieved by the fluid actuating drive according to the invention, for moving a first and a second structural part relatively to one another. A housing filled with fluid is arranged along the longitudinal direction of a slot or gap (13) which separates the first and second structure parts. The housing is shaped according to its relative position and its side walls are in contact with the first and second structural parts through its peripheral surface, alternating area-wise. The side-walls can change shape by means of a fluid, so that they move or swivel against each other, to move the structured parts against each other.
In another embodiment, a second housing can be mounted on this first housing, which is also filled with the fluid on both the sides. To change the cross-section of the first housing, fluid is circulated between the first housing and the area between it and the second housing. Adjusting movements in both the directions are possible with this arrangement.
In yet another embodiment, the fluid can be found in flexible hoses with negligible elongation, so that the housing need not be sealed.
An advantage of the invention is that, makes it possible to move large adjustment areas against one another using comparatively less equipment, since conduits are required at only a few points.
Another advantage of the invention is that with the actuator according to the invention both tension and compression movements are possible. Smaller fluid volume movements are required, so that the reservoirs otherwise need for the fluid used can be made small or eliminated. The structural parts can be held at specific positions with minimum energy consumption. Furthermore, by virtue of the invention, smaller conduit lengths are required for the fluid movements; thus, this invention proves to be favorable in respect of weight and total expenditure, such as costs. Another advantage is that a closed system is possible with this invention, which helps eliminate leakage problems almost entirely.
Since the forces are transmitted in a flat manner, the actuating drive helps avoid the concentration of larger forces, as known in the state of the art, which are usually generated in case of structural conduction of forces.
other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.